These speedring inserts have a 152mm (6") outer diameter. Available for Bowen, Paul C. Buff, Balcar, Profoto, Photogenic, Speedlights.
Flip over Front Diffuser for Quick Silver Softbox.
Cheetah Speed Pro S Bracket
Convert softboxes with a 152mm (6") Speedring Insert to work with Bowen S Mount lights and flashes